Help Alternator problem - Hyundai Performance Forums

DPHC · 06-10-2006, 01:35 PM

I was driving along and then the radio died. Next whent the fuzz buster, and the turn signals. So, I keep driving after about 10min the car starts to putter (like its running out of gas, but the tank was full) I just made it home. So i tore the car apart. I removed any aftermarket crap like the radar detector, satalight radio... Checked all the fuses, cleaned up the postes on the battery, and put it all back together. Started up the car and checked the voltage. It started up and I had 12V it slowly whent down to 11 than 10 than the car died. So thought the alternator was shot. Whent to the local Napa and picked one up. put it in, and the same crap happened. Next I tried a new battery. Same thing. So I took the alternator back to napa and had them bench test it... Its good. I have gone over all the wireing, it all looks good. the battery does not drain when the car is off. And then sometimes the voltage to the battery; when the car is running go's up to 14V but then it slowly go's down to 9V. Anyone have an idea? Because im tapped out. Thanks

DPHC · 06-11-2006, 12:55 PM

help?

Hyundai92Excel · 06-11-2006, 04:32 PM

Keep teh alternator on the vehicle and get them to do a full starting/charging test on it. It might be a bad ground or a very bad short in the system.

bizzare · 06-11-2006, 10:41 PM

Check the pcm grounds. Im im not mistaken the alternators in hyundais are controlled by the pcm, as in the ecm grounds out the voltage regulator.

DPHC · 06-12-2006, 10:56 PM

I guess I'll try swaping out the ECU with my brothers (he has a tib to) and see if that works. You said the PCM right? Is that the same thing as the ECU? As in the brain of the car? I checked all the grounds I could find, and they were all good. I diconected them and reconected them. I also noticed that at the first start up the voltage will read 14V and then after about 10 minutes it will click off and the voltage will drop to 12V and then go down after that. If i try to restart the car the alternator will not click on. But if I let the car sit for about 5-10 minutes and restart it, the alternator will come on and run for about 10 minutes and then click off again. Do you guy's know if there is some kind of internal limit in the alternator that would cause this to happen? I checked the amps on the + side of the alternator and it was at 3 amps, and it went down to about 2.5 when it shut off. this is makeing me nuts! Thanks for the replys.

meee2yo · 06-15-2006, 02:01 AM

it's probably the voltage regulator. sometimes they still test good, and can be bad. they test it at lower rpm on the bench and the belt thing, but it's normally good enough.

If the new alt did the same thing, I would think it would be a wiring thing. the computer is not going to alter the output of the alternator, you have a short or missing ground somewhere.

do the "big three" upgrade on your grounds, and run a new wire to your battery and you should be fine.

Ravinaziankid · 06-15-2006, 11:26 AM

I have this very same problem you have. I changed the battery and alternator and I have a recharge problem or something. But mine is worst since I hardly drive long distance. So I have to get a jump start everytime i want to start up the car. Who should I take it to to get this checked out from head to toe?

DPHC · 06-15-2006, 08:21 PM

I'm tring to figure out were to take my car too. I guess I'll try changing the ground wires.

Ravinaziankid · 06-16-2006, 11:18 AM

I think for my car, its the starter. I'm going to try change it this weekend. I'm crossing my fingers that its going to be fixed. I already spend over 200 for the alternator and install.

Ravinaziankid · 06-18-2006, 04:42 AM

Just an update, it was my alternator belts slipping and not giving my battery enough charge.